(1) Field of the Invention
The invention relates to guidance control means for vehicles for movement through fluid mediums, and is directed more particularly to a fin assembly for effecting guidance of such vehicles.
(2) Description of the Prior Art
It is current practice to fix marine fins, such as torpedo fins, to a shaft which, in turn, is fixed to a motor rotor within the hull of the torpedo. Upon actuation of the motor stator, the rotor turns and with it the shaft and the fin. Electrical current required for high force application to the fin can be quite high. In a confined space, such as in a torpedo, thermal limitations pose a problem. To avoid the need for high electrical currents, the motor can be equipped with large permanent magnets. However, space and weight limitation impose limitations on sizes of magnets. Further, the shaft typically is provided with splines by which the shaft is connected to a grooved portion of the fin. The splines on the motor shaft have, on occasion, stripped, so that while the shaft turns appropriately, the fin does not.
Thus, there is a need for a fin control assembly having facility for operating under high current conditions without heat buildup, and/or having relatively large permanent magnets therein, and having a reliable interconnection between the actuating means and the fin.